#include <bits/stdc++.h>
using namespace std;
void solve()
{
    string s;
    cin >> s;
    int ans=0;
    if(s.size()<5)
    {
        cout<<0<<endl;
        return;
    }
    for(int i=0;i<=s.size()-5;i++)
    {
        if(s.substr(i,5)=="edgnb")
        {
            ans++;
        }
    }
    cout<<ans<<endl;
}
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int T = 1;
    //cin >> T;
    while (T--)
    {
        solve();
    }
    return 0;
}